1. Field of the Invention
The invention is related to a binding element for alpine skis, intended to retain a boot in support on a ski, and to release the latter in case of an excessive force. More specifically, the invention is related to a front binding element.
2. Discussion of Background and Material Information
It is known to retain a boot in support on a ski by means of a front binding element and a rear binding element. Each retention element has a jaw borne by a body which is movable against the return force exerted by an energy spring, generally a compression spring.
Usually, the front binding element reacts to a lateral force of the front end of the boot. Such a force originates from a pure torsional bias on the skier's leg.
Certain binding elements also react to an upward vertical force. Such a force corresponds to a backward fall of the skier. The European Patent Application No. 102 868, for example, describes such a binding.
Other bindings have a compensation mechanism that reacts in the case of a torsional bias combined with a forward fall of the skier. Such a mechanism is described, for example, in German Patent Application No. 29 05 837. This mechanism comprises a vertically movable boot support plate whose movement, generated by a downward vertical pressure of the boot, reduces the return force that the spring exerts on the jaw.
Another mechanism is described in German Patent Application No. 33 35 878. This mechanism also comprises a vertically mobile support plate which forces the jaw to be displaced in the direction of the release of the boot. Such devices compensate for the increased friction from the boot on its supports induced by the frontward component of the fall. Such mechanisms are satisfactory as long as the lateral component of the fall remains preponderant with respect to the vertical component.
It happens that in the case of certain so-called "front-torsion" falls, i.e., with a forward component and a lateral component, the lateral component is not sufficient to generate lateral tilting of the jaw. A twisting of the boot then occurs, which boot becomes wedged between the jaw and its support plate. Currently known compensation mechanisms are not sufficiently active to generate an opening of the jaw. Sometimes these falls are dangerous and cause injuries, in particular in the area of the skier's knees.